Chris@16: 
Chris@16: // Copyright (C) 2005-2011 Daniel James
Chris@16: // Distributed under the Boost Software License, Version 1.0. (See accompanying
Chris@16: // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
Chris@16: 
Chris@16: #ifndef BOOST_UNORDERED_DETAIL_EXTRACT_KEY_HPP_INCLUDED
Chris@16: #define BOOST_UNORDERED_DETAIL_EXTRACT_KEY_HPP_INCLUDED
Chris@16: 
Chris@101: #include <boost/config.hpp>
Chris@101: #if defined(BOOST_HAS_PRAGMA_ONCE)
Chris@101: #pragma once
Chris@101: #endif
Chris@101: 
Chris@16: #include <boost/unordered/detail/table.hpp>
Chris@16: 
Chris@16: namespace boost {
Chris@16: namespace unordered {
Chris@16: namespace detail {
Chris@16: 
Chris@16:     // key extractors
Chris@16:     //
Chris@16:     // no throw
Chris@16:     //
Chris@16:     // 'extract_key' is called with the emplace parameters to return a
Chris@16:     // key if available or 'no_key' is one isn't and will need to be
Chris@16:     // constructed. This could be done by overloading the emplace implementation
Chris@16:     // for the different cases, but that's a bit tricky on compilers without
Chris@16:     // variadic templates.
Chris@16: 
Chris@16:     struct no_key {
Chris@16:         no_key() {}
Chris@16:         template <class T> no_key(T const&) {}
Chris@16:     };
Chris@16: 
Chris@16:     template <typename Key, typename T>
Chris@16:     struct is_key {
Chris@16:         template <typename T2>
Chris@16:         static choice1::type test(T2 const&);
Chris@16:         static choice2::type test(Key const&);
Chris@16:         
Chris@16:         enum { value = sizeof(test(boost::unordered::detail::make<T>())) ==
Chris@16:             sizeof(choice2::type) };
Chris@16:         
Chris@16:         typedef typename boost::detail::if_true<value>::
Chris@16:             BOOST_NESTED_TEMPLATE then<Key const&, no_key>::type type;
Chris@16:     };
Chris@16: 
Chris@16:     template <class ValueType>
Chris@16:     struct set_extractor
Chris@16:     {
Chris@16:         typedef ValueType value_type;
Chris@16:         typedef ValueType key_type;
Chris@16: 
Chris@16:         static key_type const& extract(key_type const& v)
Chris@16:         {
Chris@16:             return v;
Chris@16:         }
Chris@16: 
Chris@16:         static no_key extract()
Chris@16:         {
Chris@16:             return no_key();
Chris@16:         }
Chris@16:         
Chris@16:         template <class Arg>
Chris@16:         static no_key extract(Arg const&)
Chris@16:         {
Chris@16:             return no_key();
Chris@16:         }
Chris@16: 
Chris@16: #if !defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES)
Chris@16:         template <class Arg1, class Arg2, class... Args>
Chris@16:         static no_key extract(Arg1 const&, Arg2 const&, Args const&...)
Chris@16:         {
Chris@16:             return no_key();
Chris@16:         }
Chris@16: #else
Chris@16:         template <class Arg1, class Arg2>
Chris@16:         static no_key extract(Arg1 const&, Arg2 const&)
Chris@16:         {
Chris@16:             return no_key();
Chris@16:         }
Chris@16: #endif
Chris@16:     };
Chris@16: 
Chris@16:     template <class Key, class ValueType>
Chris@16:     struct map_extractor
Chris@16:     {
Chris@16:         typedef ValueType value_type;
Chris@16:         typedef typename boost::remove_const<Key>::type key_type;
Chris@16: 
Chris@16:         static key_type const& extract(value_type const& v)
Chris@16:         {
Chris@16:             return v.first;
Chris@16:         }
Chris@16:             
Chris@16:         template <class Second>
Chris@16:         static key_type const& extract(std::pair<key_type, Second> const& v)
Chris@16:         {
Chris@16:             return v.first;
Chris@16:         }
Chris@16: 
Chris@16:         template <class Second>
Chris@16:         static key_type const& extract(
Chris@16:             std::pair<key_type const, Second> const& v)
Chris@16:         {
Chris@16:             return v.first;
Chris@16:         }
Chris@16: 
Chris@16:         template <class Arg1>
Chris@16:         static key_type const& extract(key_type const& k, Arg1 const&)
Chris@16:         {
Chris@16:             return k;
Chris@16:         }
Chris@16: 
Chris@16:         static no_key extract()
Chris@16:         {
Chris@16:             return no_key();
Chris@16:         }
Chris@16: 
Chris@16:         template <class Arg>
Chris@16:         static no_key extract(Arg const&)
Chris@16:         {
Chris@16:             return no_key();
Chris@16:         }
Chris@16: 
Chris@16:         template <class Arg1, class Arg2>
Chris@16:         static no_key extract(Arg1 const&, Arg2 const&)
Chris@16:         {
Chris@16:             return no_key();
Chris@16:         }
Chris@16: 
Chris@16: #if !defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES)
Chris@16:         template <class Arg1, class Arg2, class Arg3, class... Args>
Chris@16:         static no_key extract(Arg1 const&, Arg2 const&, Arg3 const&,
Chris@16:                 Args const&...)
Chris@16:         {
Chris@16:             return no_key();
Chris@16:         }
Chris@16: #endif
Chris@16: 
Chris@16: #if !defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES)
Chris@16: 
Chris@16: #define BOOST_UNORDERED_KEY_FROM_TUPLE(namespace_)                          \
Chris@16:         template <typename T2>                                              \
Chris@16:         static no_key extract(boost::unordered::piecewise_construct_t,      \
Chris@16:                 namespace_ tuple<> const&, T2 const&)                       \
Chris@16:         {                                                                   \
Chris@16:             return no_key();                                                \
Chris@16:         }                                                                   \
Chris@16:                                                                             \
Chris@16:         template <typename T, typename T2>                                  \
Chris@16:         static typename is_key<key_type, T>::type                           \
Chris@16:             extract(boost::unordered::piecewise_construct_t,                \
Chris@16:                 namespace_ tuple<T> const& k, T2 const&)                    \
Chris@16:         {                                                                   \
Chris@16:             return typename is_key<key_type, T>::type(                      \
Chris@16:                 namespace_ get<0>(k));                                      \
Chris@16:         }
Chris@16: 
Chris@16: #else
Chris@16: 
Chris@16: #define BOOST_UNORDERED_KEY_FROM_TUPLE(namespace_)                          \
Chris@16:         static no_key extract(boost::unordered::piecewise_construct_t,      \
Chris@16:                 namespace_ tuple<> const&)                                  \
Chris@16:         {                                                                   \
Chris@16:             return no_key();                                                \
Chris@16:         }                                                                   \
Chris@16:                                                                             \
Chris@16:         template <typename T>                                               \
Chris@16:         static typename is_key<key_type, T>::type                           \
Chris@16:             extract(boost::unordered::piecewise_construct_t,                \
Chris@16:                 namespace_ tuple<T> const& k)                               \
Chris@16:         {                                                                   \
Chris@16:             return typename is_key<key_type, T>::type(                      \
Chris@16:                 namespace_ get<0>(k));                                      \
Chris@16:         }
Chris@16: 
Chris@16: #endif
Chris@16: 
Chris@16: BOOST_UNORDERED_KEY_FROM_TUPLE(boost::)
Chris@16: 
Chris@16: #if !defined(BOOST_NO_CXX11_HDR_TUPLE)
Chris@16: BOOST_UNORDERED_KEY_FROM_TUPLE(std::)
Chris@16: #endif
Chris@16:     };
Chris@16: }}}
Chris@16: 
Chris@16: #endif